Internal combustion engine



Nov. 23, 1943. T. JACKSON 2,335,136

INTERNAL COMBUSTION ENGINE I Original Filed April '7, 1941' 2 s t she t1 INVENTOR. 01

Tfioma Jae/man Nov. 23, 1943. V T. JACKSQN 2,335,185

INTERNAL COMBUSTION ENGINE Original Filed April 7, 1941 2 5 t t 2STARTER Jnvcntor 0 Jackson 3143. 2 N B! 2 attorney,

Patented Nov. 23, 1943 2,335,186 INTERNAL COMBUSTION ENGINE ThomasJackson, North Mnskegon, Mich., assignor to Continental MotorsCorporation, De-

troit, Mich, a corporation of Virginia Original application April "7,1941, Serial No. 387,146,'now Patent No. 2,311,944, issued February 23,1943.

Divided and this application necembera, 1941, Serial N0. 422,078 6Claims, (01. 123-195) My invention relates to aircraft internalcombustion engines and more particularly to the accessory gear mechanismand assembly.

One of the objects of my present invention. is to improve engineperformance and facilitate engine assembly and maintenance by providingan improved compact accessory drive assembly wherein the driving meansare so positioned and assembled together as to comprise a compactassembly which is very readily put together in a gear case of compactoverall dimensions.

A further object of my present invention relates to the accessorymechanism in general and more particularly to an improved oil pumpassembly and drive. I

Still further objects of my present invention re late to variousfeatures and structural details, which result in the construction of anaccessory gear case assembly of minimum size and weight.

A still further object of my invention is to construct an improved oilpump drive by providing a structure wherein the oil pump is axiallyaligned with the engine camshaft and directly driven thereby.

Fora more detailed understanding of my invention reference may be had tothe accompanying drawings illustrating the various features of myimproved accessory gear mechanism and assembly, and in which:

Fig. 1 is a rear elevational View of the engine showing the variousaccessories assembled there- Fig. 2 is a vertical sectional view throughthe rear end engine construction and taken substantially on the line2--2 of Fig. l, and

Fig. 3 is a sectional view illustrating the oil pump construction anddrive, taken substantially on the line 3-3 of Fig. 2.

This application for patent is a division of my co-pending application,Ser. No. 387,146, filed April 7, 1941 now Patent No. 2,311,944, issuedFebruary 23, 1943 for Internal combustion engines.

I have chosen for purposes of'illustration to illustrate my presentinvention in connection with a conventional aircraft internal combustionengine'having a crankcase structure [0, which include a rear transversewallportion provided with suitable bearing means for supporting theengine crankshaft |2, cam shaft i3 and other associated devices such asthe stub shaft or pilot shaft M. An accessory gear housing, is bolted orotherwise secured to the crankcase I and it will be noted that this gearhousing is preferably secured to the rear end face of the crankcase, andis of a minimum thickness by reason of the compact assembly of thevarious accessory gears housed therein.

Said accessory gear housing I5 is preferably open as at l6 for thedrainage of lubricant into an oil sump (not shown) attached to theunderside of the engine and gear housing. The rear face of the gearhousing is machined in accordance with predetermined designto provide astarter pad ll,

shaft starter gear 3|].

to which a conventional 6 or 12 volt starter I8 is secured by means ofbolts or other suitable fastening devices l9.

It will be observed that the starter preferably carries the end plate 20secured againstthe pad l1, and which-is provided with 9. depending earportion 2| that carries a bearing 22 for supporting the shank 23 of theshiftable intermediate compound reduction gear 24. The shank 23 of thiscompound gear is engaged by an arm 25, which is actuated in timedrelation with the electric starter control 21. The arm 25 is manuallyshifted or rocked to push on said shank 23 and to then cut in theelectric switch or control 21. Thus, on starting the said starter, thecompound gear 24 is shifted axially into engagement with the crank- Moreparticularly, this compound gear comprises a hub 3| preferably formedintegral with the shaft or shank 23, and carries the large diameter gear32 which is in mesh with the starter gear 33. As the intermediatecompound gear is axially shifted to the dotted position shown in Fig. 2,it will be noted that the large diameter gear 32 remains in mesh withthe starter gear 33. Said hub 3| of the compound gear carries a smallgear extension 34 which is recessed to receive the stub shaft or pilotshaft 4. As this compound gear is shifted to the left into the dottedline position (see Fig. 2) the small gear 34 is moved into meshingengagement with the crank shaft starter gear 30, which is preferablysecured to the crankshaft |2 by means of bolts 36. A spring or othersuitable resilient means of conventional construction, which isdesignated 31, is operable to retract the compound gear or move the sameout of engagement with the crankshaft starter gear when the. electricalcurrent to the starter is switched off.

The crankshaft starter gear is of the compound type, and also provides agear 40 of smaller pitch diameter than gear 30, this gear 40 meshingwith a gear 4| secured by bolts 42 to the flange 43 carried by the camshaft l3. This cam shaft gear 4| carries integrally therewith aninternal gear 44, to which may be meshed the driven gear 45 associatedwith the generator 46 and preferably connected with the generatorarmature shaft by a flexible coupling 45a.

Axially located on the cam shaft gear is a recess 43a which is flattenedor squared to receive the end 41 of the oil pump driving shaft 48incorporated with the oil pump structure 49, and preferably formedintegral with the driving gear 60 of the oil pump and supported in usualhearings in the oil pump housing 5|. The driven gear 52 of the oil pumpis provided with a shaft extension 53 projecting rearwardly through thehousing l5 and constructed for driving connection with an engineaccessory, such as the tachometer 54.

It will thus be observed that the oil pump projects inwardly of theinternal ring gear 44 and the driving gear of the oil pump has a shaftextension which is directly driven by the cam shaft gear. The oil pumpdriving gear is thus axially aligned with the cam shaft and is assembledrelatively closely adjacent to the cam shaft gear thus providing a verycompact assembly, and the whole accessory gear assembly and housing isthus of minimum weight and size and particularly applicable to anaircraft engine.

The particular assembly, also incorporated gear mountings which supportthe various accessory mechanisms, are located in such a way that theaccessory gears all rotate about axes extending parallel to thecrankshaft axis. Incidentally, it will be observed that the magnetogears 60 and 60a (Fig. 3) are in constant mesh with and driven by thecam shaft gear ll.

Although I have illustrated but one form of my invention and havedescribed in detail but a single application thereof, it will beapparent to those skilled in the art to which my invention pertains,that various modifications and changes may be made therein withoutdeparting from the spirit of my invention or from the scope of theappended claims.

I claim:

1. Accessory gear mechanism for an aircraft internal combustion enginehaving a crankshaft carrying a crankshaft driving gear, a camshaft geardrivingly connected with the crankshaft driving gear and carrying aninternal ring gear,

internal ring gear, and an oil pumping instrumentality adjacent to saidcam shaft gear and extended in part axially within the internal. ringgear, said oil pumping instrumentality including a driving gear and adriven gear, said driving gear axially aligned with said camshaft gearand directly drivingly connected therewith.

2. Accessory gear mechanism for an aircraft internal combustion enginehaving a crankshaft carrying a crankshaft driving gear, a camshaft geardrivingly connected with the crankshaft driving gear and carrying aninternal ring gear, a generator gear drivingly connected with saidinternal ring gear, and an oil pumping instrumentality adjacent to saidcamshaft gear and extended in part axially within the internal ringgear, said oil pumping instrumentality including a driving gear and adriven gear, said driving gear axially aligned with said camshaft gearand directly drivingly connected therewith, said oil pump driven gearhaving a shaft extension axially aligned with and drivingly connectedwith an engine accessory.

3. Accessory gear mechanism for an aircraft internal combustion enginehaving a crankshaft carrying a crankshaft driving gear, a camshaft geardrivingly connected with the crankshaft driving gear, and a plurality ofengine accessories drivingly connected with said camshaft gear andincluding an oil pump supported adjacent to the rear face of saidcamshaft gear and including a driving gear and a driven gear, said oilpump driving gear axially aligned with said camshaft gear and directlydriven thereby.

4. Accessory gear mechanism for an aircraft internal combustion enginehaving a crank-- shaft carrying a crankshaft driving gear, a camshaftgear drivingly connected with the crankshaft driving gear, and aplurality of engine accessories drivingly connected with said camshaftgear and including an oil pump supported relatively closely adjacent tothe rear face of said camshaft gear and including a. driving gear and adriven gear, said oil pump driving gear axially aligned with saidcamshaft gear and provided with an axially extended stub shaft directlyconnected with said camshaftgear.

5. Accessory gear mechanism for an aircraft internal combustion enginehaving a crankshaft carrying a crankshaft driving gear, an accessorygear housing, a camshaft, a camshaft gear drivingly connected with thecrankshaft driving gear and including an internal ring gear, a generatorsupported by said housing and including a driven shaft extended withinthe housing, a pinion meshing with the internal ring gear, and a,flexible coupling connecting said pinion with the driven shaft of saidgenerator.

6. Accessory gear mechanism for an aircraft internal combustion enginehaving a crankshaft carrying a crankshaft driving gear, a camshaft agenerator gear drivingly connected with sailextending Parallel to Saidcrankshaft and carrying a concentric camshaft gear drivingly connectedwith the crankshaft driving gear, said camshaft driving gear comprisinga structure having a hub portion and constructed to provide an internalring gear concentric to said camshaft driving gear, and a plurality ofengine accessories driven by said structure and including a generatordrive gear drivingly connected with said internal ring gear, and an oilpump instrumentality including an oil pump driving gear aligned withsaid camshaft, and having an axially extending shaft directly drivinglyconnected with the said hub portion of said camshaft driving gearstructure.

THOMAS JACKSON.

